Reliability Analysis Of Power Grid Considering The Meteorological Information

With the rapid development of power system,global warming and haze are becoming severe,plus,the increase of strong convective weather and changeable climate,the transmission line and transmission tower fault,causing by extreme climate,occur frequently,which seriously threaten the safety and reliability of power system.Ice storm(freezing)is a common phenomenon in winter,and its duration is very long,which brings the obvious impact to transmission line and transmission tower,leading to the break of transmission line and the collapse of transmission tower,easily.High temperature in summer,occurring the increase of transmission line sag,which increase the risk of flashover.At the same time,the load demand increases during the time,causing transmission line needs to deliver more power,which increase the risk of power transmission limitation.The summer is also prone to the phenomenon of the storm,which leads to the transmission line and the transmission tower oscillation,leading to the occurrence of the accident.Meanwhile,in some areas,storm will do damage to the tower foundation,which exacerbating the risk of tower collapse.Lighting,which duration is very short and variable.The transmission line outage events caused by the lightning is a great proportion to the statistics of power grid fault According to the different natural disasters,especially in the large range of extremely weather disasters,which are more serious than the damage caused by the electrical hazard.The research on the reliability analysis of power grid considering the meteorological information,which is becoming more important.In view of the above problems,the paper further studies the meteorological warning system of Anhui power system,considering the meteorological information.The content and main results of this paper are as follows:(1)Present the improved model and its solving method of the break of transmission line and the collapse of transmission tower,causing by the combination of ice and wind load: using "Peak Method" to calculate the threshold parameters,which are for freezing precipitation and wind speed of the generalized Pareto distribution(GPD);the effective method for solving the double integral in ice and wind load model is put forward;calculate of unbalanced tension on both sides of the transmission tower,considering time varying characteristics of the wind speed.(2)The model for the combination of temperature and sag is established.According to this model,the index of sag risk is proposed,which is used to evaluate the impact on the safety operation of transmission line,causing by the sag.And then,the sag outage probability of transmission line is obtained.Furthermore,analysis the outage probability of transmission line,considering the power flow of line and the extra environment factor(high temperature)and establish the comprehensive outage probability model of transmission line.(3)Study on the reliability and the outage probability of transmission lines under the condition of the action of rain load and wind load.The outage probability of transmission line,causing by rain load or wind load,is established,separately;put forward the transacting factor for rain load,which aims to reflect the transmission tower,which is under the condition of rain load,transacting the transmission line.As is similar to the wind load.Plus,the joint outage probability model of the transmission line under the action of wind and rain is established.And the model is verified.(4)On the basis of in-depth understanding of the new calculation method,which is based on the information at three adjacent time interval,calculating the probability of lightning trip in power system.Lightning flashover warning model for transmission line and failure probability analysis and warning model for transmission line are proposed,which are used to improve the above model.